A composition for air disinfection and deodorization and its preparation method

Abstract

The present invention belongs to the technical field of air disinfection and sterilization, and particularly relates to a composition for air disinfection and deodorization and a preparation method thereof. The composition includes a core component and a shell component; the core component includes the following components: sodium alginate, chitosan, potassium monopersulfate, tannic acid, zinc nitrate, glycerol, sodium chloride, and calcium chloride; the shell component includes the following components: plant essential oil, pregelatinized starch, polyethylene glycol, nano-silica, hydroxypropyl methylcellulose, polydimethylsiloxane, and silane coupling agent; The present invention innovatively combines the intrinsic characteristics of natural materials with the dynamic regulation of the core-shell structure, breaks through the competitive failure caused by the stacking of chemical components in traditional technologies, and realizes the air purification effect of the synergism of multiple natural active substances.

Description

Technical Field

[0001] The present invention belongs to the technical field of air disinfection and sterilization, and particularly relates to a composition for air disinfection and deodorization and a preparation method thereof. Background Art

[0002] The acceleration of the urbanization process and the trend of indoor environmental enclosure have transformed air pollution from a single particulate matter problem into a complex challenge covering biological and chemical hazards. Pathogenic microorganisms in the air (such as drug-resistant bacteria, enveloped viruses, fungal spores) and volatile odor molecules (such as aldehydes, sulfides, ammonia) pose a dual threat, and their synergistic effect is particularly prominent in high-density places such as medical spaces and public transportation, not only increasing the risk of cross-infection but also easily triggering chronic respiratory diseases or sensory discomfort. Although traditional purification technologies have their own advantages, they are restricted by the inherent bottlenecks of physical or chemical properties: Ultraviolet sterilization relies on direct light paths, making it difficult to penetrate complex spatial structures and posing strict requirements for equipment maintenance and personnel protection; Although ozone oxidation has strong disinfection and killing capabilities, its chemical activity is likely to cause mucosal irritation, especially in poorly ventilated scenarios, which may lead to secondary health risks; Activated carbon adsorption relies on porous physical interception and is prone to saturation inactivation when facing continuously released odors or high-concentration pollutants, resulting in pulsed fluctuations in purification efficiency and making it difficult to maintain a stable environmental quality.

[0003] In recent years, the compatibility problem between different active ingredients has not been effectively solved. For example, some oxidative disinfection components are prone to react with plant essential oil substances and become ineffective, and precipitates may be generated after mixing quaternary ammonium salt compounds with certain metal catalysts. Existing compositions generally have the problem of a single action target and cannot simultaneously destroy the cell structure of microorganisms and the chemical bonds of odor molecules, resulting in the difficulty of breaking through the treatment efficiency. In addition, the degradation by-products of chemical disinfectants (such as halogenated compounds, residual monomers) may penetrate into the ecosystem, triggering concerns about environmental tolerance and bioaccumulation. These contradictions highlight the imbalance of existing technologies in terms of broad-spectrum, environmental compatibility, and long-term safety. Therefore, in this context, it is of great significance to develop a safe and efficient composite air purification composition with both disinfection and deodorization functions. Summary of the Invention

[0004] Aiming at the defects of the existing technology, the purpose of the present invention is to provide a composition for air disinfection and deodorization and a preparation method thereof.

[0005] The technical effects of the present invention are achieved through the following technical solutions: A composition for air disinfection and deodorization, which comprises a core component and a shell component; the core component comprises the following components: sodium alginate, chitosan, potassium monopersulfate, tannic acid, zinc nitrate, glycerol, sodium chloride, and calcium chloride; the shell component comprises the following components: plant essential oil, pregelatinized starch, polyethylene glycol, nano-SiO2, hydroxypropyl methylcellulose, polydimethylsiloxane, and silane coupling agent;

[0006] Preferably, the plant essential oil is prepared from eucalyptus oil, lavender oil, peppermint oil, and clove bud oil, and the specific preparation steps are as follows:

[0007] Step 1: Preheat eucalyptus oil at 50°C for 20 - 30 min under nitrogen protection, and then perform staged distillation; filter through a 0.45 μm nylon filter membrane at 60°C to obtain pretreated eucalyptus oil; let lavender oil stand at 4°C for 48 h, and filter to remove wax using a diatomaceous earth coating to obtain pretreated lavender oil; precool peppermint oil at -25 to -20°C for 12 h, and then centrifuge at -20 to -15°C and 8000 - 10000 rpm for 30 min under nitrogen protection to obtain pretreated peppermint oil;

[0008] Step 2: Stir the pretreated eucalyptus oil and pretreated lavender oil prepared in Step 1 at 35 - 42°C for 10 - 20 min under nitrogen protection, then add the pretreated peppermint oil, stir at 2000 rpm for 20 - 30 min, add clove bud oil and 2 - 3% Tween - 80, perform ultrasonic treatment, add 0.1% vitamin E, mix well, and let stand at 4°C for 24 h to obtain the plant essential oil;

[0009] Preferably, in Step 1, the staged distillation step is evaporation at 85°C, condensation at -10°C, distillation at 0.8 mbar, and discard the first 5% of the distillate; then raise the temperature to 95 - 105°C, distill at 0.5 mbar, and discard the first 5% and the last 10% of the distillate;

[0010] Preferably, in Step 1, the wax removal filtration step is to use a pre - coating of diatomaceous earth with a wet - based thickness of 5 mm and a pore size of 10 μm, increase the pressure from 0.1 MPa to 0.25 MPa at a rate of 0.01 MPa / min at 10 - 15°C, and filter at a filtration rate of 1 - 1.5 L / m 2 •h, and repeat the filtration process three times;

[0011] Preferably, in Step 2, the volume ratio of the pretreated eucalyptus oil, pretreated lavender oil, pretreated peppermint oil, and clove bud oil is 4.5 - 5:2 - 3:1.5 - 2.5:0.5 - 1; the ultrasonic treatment parameters are 60 - 80 W, 20 kHz, and the time is 5 - 8 min;

[0012] Preferably, the silane coupling agent is any one of octyltriethoxysilane, dodecyltrimethoxysilane and hexadecyltrimethoxysilane; further preferably, it is hexadecyltrimethoxysilane;

[0013] Preferably, on the other hand, the present invention provides a method for preparing a composition for air disinfection and deodorization, and the specific preparation steps are as follows:

[0014] Step 1: Stir and mix a 2-3 wt% sodium alginate solution and glycerol evenly, then add a 1-2 wt% chitosan solution, stir and mix evenly, then successively add 0.15-0.2% zinc nitrate and 1-1.5% tannic acid, adjust the pH to 5, and continue stirring until homogeneous to obtain a precursor solution;

[0015] Step 2: Slowly drop the precursor solution prepared in Step 1 into a 3 wt% calcium chloride and 0.05 M sodium chloride solution, maintain the temperature at 4°C, slowly stir for 30-60 min, wash with deionized water, freeze-dry at -40°C for 12-24 h, then immerse in a 0.5 wt% potassium monopersulfate solution, oscillate at 25°C for 2 h, repeat washing with deionized water 3 times, and freeze-dry at -40°C for 12 h to obtain the core;

[0016] Step 3: Disperse nano-SiO2 in absolute ethanol, perform ultrasonic dispersion treatment at 60 W for 15-20 min, add a silane coupling agent, adjust the pH to 4.5-5.5, react under nitrogen protection in a water bath at 60-65°C for 6 h, centrifuge, repeat washing with ethanol 3 times, and vacuum-dry at 60°C for 12 h to obtain modified nano-SiO2; Disperse pregelatinized starch, hydroxypropyl methylcellulose, modified nano-SiO2 and polyethylene glycol in deionized water in sequence, adjust the pH to 6, perform ultrasonic treatment at 60 W for 20-30 min to obtain a pretreated slurry; Preheat the core prepared in Step 2 at 50°C for 10 min, then evenly spray the pretreated slurry, treat at 70°C and 85% humidity for 2 h, and dry at 50°C for 1-2 h to obtain coated particles;

[0017] Step 4: Add the coated particles prepared in Step 3 to the plant essential oil preheated to 40°C, soak under vacuum conditions for 35-60 min, and centrifuge at 1200 rpm for 3-5 min to obtain loaded particles;

[0018] Step 5: Spray a 1.5 wt% polydimethylsiloxane n-hexane solution on the loaded particles prepared in Step 4; after the spraying treatment, treat at 30°C and 85% humidity for 30-60 min, then treat at 40°C and 50% humidity for 3 h, and then repeat the cycle treatment to obtain the disinfection and deodorization composition;

[0019] Preferably, in step 1, the sodium alginate solution and the chitosan solution are prepared by mixing sodium alginate and chitosan with deionized water; the volume ratio of the sodium alginate solution, glycerol and chitosan solution is 1:0.08-0.12:1-1.5;

[0020] Preferably, in step 3, the ratio of the amount of the nano-SiO2, anhydrous ethanol and silane coupling agent is 1g:150mL:5-6mL; the ratio of the amount of the pregelatinized starch, hydroxypropyl methylcellulose, modified nano-SiO2 and deionized water is 3-4g:0.8-1.2g:1.5-2g:120mL; the amount of the polyethylene glycol is 4% of the substrate mass;

[0021] Preferably, in step 3, the spraying pretreatment slurry is operated at 50-55°C air inlet, 1-1.5 bar atomization pressure, 5 mL / min spray rate, and 10-15 min;

[0022] Preferably, in step 4, the ratio of the amount of the shelled particles to the plant essential oil is 1 g: 0.35-0.45 mL;

[0023] Preferably, in step 5, the spraying operation is performed at 0.3 MPa, a spraying distance of 20 to 25 cm, and a spraying volume of 5 to 8 mL / m 2 , spray twice with an interval of 10 minutes, dry with hot air at 40℃ for 1-2 hours, and then cure at 70-80℃ for 20-30 minutes;

[0024] Preferably, in step five, the repeated cycle treatment operation is 30° C. and 75% humidity for 30 minutes, then 40° C. and 30% humidity for 2 hours, and the cycle treatment is repeated twice.

[0025] The beneficial effects of the present invention are as follows:

[0026] The present invention realizes the synergistic effect of disinfection, deodorization and air purification by combining multiple technical means; in the raw material pretreatment stage, the composite essential oil is optimized and adapted in a targeted manner, specifically, the eucalyptus oil is fractionally distilled to remove low-polarity resin substances, and the medium-polarity 1,8-cineole is retained, which not only enhances the hydrogen bond binding force between the eucalyptus oil and the shell nano-SiO2, but also reduces the residual risk of high-boiling point impurities in the pores; the lavender oil is then filtered at low temperature to remove wax, and small molecular active substances such as linalyl acetate and linalool are retained, taking into account both rapid diffusion and pore patency; finally, the peppermint oil is frozen and crystallized to purify menthol, and the borneol is eliminated to remove zinc ions (Zn 2+) complex interference. Based on the above treatment process, a multi-level synergistic system is constructed: at the level of disinfection and antibacterial, eucalyptol destroys the lipid bilayer of the outer membrane of Gram-negative bacteria and inhibits ATP synthase, and eugenol in clove bud oil interferes with the intracellular enzyme activity by attacking the hydrophobic region of microbial membrane proteins through phenolic hydroxyl groups, and cooperates with zinc ions (Zn 2+ ) to interfere with DNA replication; menthol plays a synergistic role by dissolving the chitin structure of fungi; at the level of deodorization, menthol quickly neutralizes sulfur-containing odor molecules, the ester group of lavender oil decomposes nitrogen-containing compounds for a long time, and the terpenes of eucalyptus oil and the phenolic hydroxyl group of eugenol cooperate to catalyze the degradation of pollutants. For the core-shell carrier structure, the present invention fixes the tannic acid and zinc nitrate complex through the interpenetrating network of sodium alginate-chitosan-Ca 2+ to achieve humidity-responsive release by utilizing the dynamic coordination equilibrium between the polyphenolic hydroxyl groups of tannic acid and zinc ions; a core-shell structure is constructed by using pregelatinized starch and nano-SiO2. The pregelatinized starch quickly adsorbs essential oils through capillary action and is supported by its porous skeleton. After the surface of nano-SiO2 is hydrophobically modified with hexadecyltrimethoxysilane (HDTMS), a dense alkyl chain barrier layer is formed. The diffusion path of essential oil molecules is synergistically regulated through the hydrophobic repulsion effect and pore effect of the alkyl chain, so as to achieve the regulation of the volatilization rate of essential oils. In addition, the pregelatinized starch in the shell layer forms an interfacial interlock with sodium alginate in the core layer through hydrogen bonds to prevent the shell layer from peeling off, and the long-chain alkyl groups of HDTMS form a physical interpenetrating network with the hydrophobic membrane of polydimethylsiloxane (PDMS) through intermolecular hydrophobic interactions to enhance the interfacial binding strength and prevent interfacial peeling. In terms of the dynamic regulation mechanism, the hydroxypropyl methyl cellulose (HPMC) in the shell layer swells and expands to open pores when the humidity is high, triggering the formation of microcracks in the hydrophobic membrane of polydimethylsiloxane, realizing humidity-responsive release and accelerating the release of essential oils; polydimethylsiloxane also plays the functions of blocking oxygen and ultraviolet rays at the same time, and its compactness and the alkyl chain barrier of HDTMS cooperate to inhibit the oxidative cross-linking of terpenoid substances, prevent the oxidative cross-linking of terpenoid substances in essential oils, and maintain the stability of active ingredients. In summary, the present invention innovatively combines the intrinsic characteristics of natural materials with the dynamic regulation of the core-shell structure, breaks through the competitive failure caused by the stacking of chemical components in traditional technologies, and realizes the air purification effect of the synergism of multiple natural active substances. Description of the Drawings

[0027] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only those of the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative efforts.

[0028] Figure 1 It is a test result diagram of disinfecting and sterilizing Escherichia coli of the compositions prepared in Example 2 and Comparative Examples 1-4 of the present invention;

[0029] Figure 2 It is a test result diagram of disinfecting and sterilizing Staphylococcus aureus of the compositions prepared in Example 2 of the present invention and Comparative Examples 1-4;

[0030] Figure 3 It is a test result diagram of disinfecting and sterilizing Aspergillus niger of the compositions prepared in Example 2 of the present invention and Comparative Examples 1-4;

[0031] Figure 4 It is a test result diagram of H2S for air deodorization of the compositions prepared in Example 2 of the present invention and Comparative Examples 1-4;

[0032] Figure 5 It is a test result diagram of NH3 for air deodorization of the compositions prepared in Example 2 of the present invention and Comparative Examples 1-4;

[0033] Figure 6 It is a test result diagram of the mechanical strength of the compositions prepared in Example 2 of the present invention and Comparative Examples 1-4. Detailed implementation manners

[0034] Next, in combination with the embodiments of the present invention, the technical solutions of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention. It should be noted that unless otherwise specified, the raw materials involved in the present invention are purchased through conventional commercial channels.

[0035] Example 1: A composition for air disinfection and deodorization, which comprises a core component and a shell component; the core component includes the following components: sodium alginate, chitosan, potassium monopersulfate, tannic acid, zinc nitrate, glycerol, sodium chloride and calcium chloride; the shell component includes the following components: plant essential oil, pregelatinized starch, polyethylene glycol, nano-SiO2, hydroxypropyl methylcellulose, polydimethylsiloxane and silane coupling agent;

[0036] The plant essential oil is prepared from eucalyptus oil, lavender oil, peppermint oil and clove bud oil, and the specific preparation steps are as follows:

[0037] Step 1: Preheat 100 mL of eucalyptus oil under nitrogen protection at 50 °C for 20 min, then perform fractional distillation. Evaporate at 85 °C, condense at -10 °C, and distill at 0.8 mbar. Discard the first 5% of the distillate; then raise the temperature to 95 °C and distill at 0.5 mbar. Discard the first 5% and the last 10% of the distillate; filter through a 0.45 μm nylon filter membrane at 60 °C to obtain pretreated eucalyptus oil; Let 100 mL of lavender oil stand at 4 °C for 48 h, filter to remove wax using a diatomaceous earth coating. Use a precoat of diatomaceous earth with a wet basis thickness of 5 mm and a pore size of 10 μm. At 15 °C, increase the pressure from 0.1 MPa to 0.25 MPa at a rate of 0.01 MPa / min, and filter at a filtration rate of 1 L / m 2 •h. Repeat the filtration process three times to obtain pretreated lavender oil; Precool 100 mL of peppermint oil at -25 °C for 12 h, then centrifuge at -20 °C and 8000 rpm for 30 min under nitrogen protection to obtain pretreated peppermint oil;

[0038] Step 2: Under nitrogen protection, stir 45 mL of the pretreated eucalyptus oil prepared in Step 1 and 20 mL of the pretreated lavender oil at 35 °C for 20 min, then add 15 mL of the pretreated peppermint oil and stir at 2000 rpm for 20 min. Dropwise add 5 mL of clove bud oil and 1.7 mL of Tween-80, and perform ultrasonic treatment at 60 W and 20 kHz for 8 min; Add 0.085 g of vitamin E, mix well, and let stand at 4 °C for 24 h to obtain the essential oil;

[0039] The specific preparation steps of the composition for air disinfection and deodorization are as follows:

[0040] Step 1: Stir and mix 100 mL of 2 wt% sodium alginate solution and 8 mL of glycerol evenly, then mix with 100 mL of 1 wt% chitosan solution, stir and mix evenly, and then add 0.3 g of zinc nitrate and 2 g of tannic acid in sequence. Adjust the pH to 5 and continue stirring until homogeneous to obtain the precursor solution;

[0041] Step 2: Slowly drip 200 mL of the precursor solution prepared in Step 1 into 400 mL of 3 wt% calcium chloride and 0.05 M sodium chloride solution, maintain the temperature at 4 °C, slowly stir for 30 min, wash with deionized water, freeze-dry at -40 °C for 12 h, then immerse in 400 mL of 0.5 wt% potassium monopersulfate solution, oscillate at 25 °C for 2 h, repeat washing with deionized water 3 times, and freeze-dry at -40 °C for 12 h to obtain the core;

[0042] Step 3: Disperse 2 g of nano-SiO₂ in 300 mL of absolute ethanol, perform ultrasonic dispersion treatment at 60 W for 15 min, add 10 mL of octyltriethoxysilane, adjust the pH to 4.5, react in a water bath at 60 °C under nitrogen protection for 6 h, centrifuge, wash repeatedly with ethanol 3 times, and dry in vacuum at 60 °C for 12 h to obtain modified nano-SiO₂; Disperse 3 g of pregelatinized starch, 0.8 g of hydroxypropyl methylcellulose, 1.5 g of modified nano-SiO₂, and 0.212 g of polyethylene glycol in 120 mL of deionized water in sequence, adjust the pH to 6, and perform ultrasonic treatment at 60 W for 20 min to obtain a pretreated slurry; Preheat the 10 g of core prepared in Step 2 at 50 °C for 10 min, then uniformly spray the pretreated slurry, with an inlet air temperature of 50 °C, an atomization pressure of 1 bar, a liquid spraying rate of 5 mL / min, and a time of 15 min; Treat at 70 °C with a humidity of 85% for 2 h, and dry at 50 °C for 1 h to obtain coated particles;

[0043] Step 4: Add the 10 g of coated particles prepared in Step 3 to 3.5 mL of plant essential oil preheated to 40 °C, soak under vacuum conditions for 35 min, and centrifuge at 1200 rpm for 3 min to obtain loaded particles;

[0044] Step 5: Spray a 1.5 wt% polydimethylsiloxane n-hexane solution on the 10 g of loaded particles prepared in Step 4. Under 0.3 MPa, the spraying distance is 20 cm, and the spraying amount is 5 mL / m 2 , spray 2 times at intervals of 10 min, dry with hot air at 40 °C for 2 h, and then cure at 70 °C for 30 min after the spraying treatment; After the spraying treatment, treat at 30 °C and 85% humidity for 30 min, then treat at 40 °C and 50% humidity for 3 h, then repeat the cyclic treatment, treat at 30 °C and 75% humidity for 30 min, then treat at 40 °C and 30% humidity for 2 h, and perform the cyclic treatment 2 times to obtain a disinfection and deodorization composition.

[0045] Example 2: A composition for air disinfection and deodorization, which comprises a core component and a shell component; The core component includes the following components: sodium alginate, chitosan, potassium peroxymonosulfate, tannic acid, zinc nitrate, glycerol, sodium chloride, and calcium chloride; The shell component includes the following components: plant essential oil, pregelatinized starch, polyethylene glycol, nano-SiO₂, hydroxypropyl methylcellulose, polydimethylsiloxane, and silane coupling agent;

[0046] The plant essential oil is prepared from eucalyptus oil, lavender oil, peppermint oil, and clove bud oil, and the specific preparation steps are as follows:

[0047] Step 1: Preheat 100 mL of eucalyptus oil under nitrogen protection at 50 °C for 30 min, then perform fractional distillation treatment. Evaporate at 85 °C, condense at -10 °C, and distill at 0.8 mbar. Discard the first 5% of the distillate; then raise the temperature to 105 °C and distill at 0.5 mbar. Discard the first 5% and the last 10% of the distillate; filter through a 0.45 μm nylon membrane at 60 °C to obtain pretreated eucalyptus oil; Let 100 mL of lavender oil stand at 4 °C for 48 h, filter and remove wax using a diatomaceous earth coating. Use a precoat of diatomaceous earth with a wet basis thickness of 5 mm and a pore size of 10 μm. At 10 °C, increase the pressure from 0.1 MPa to 0.25 MPa at a rate of 0.01 MPa / min and filter at a filtration rate of 1.5 L / m 2 •h. Repeat the filtration treatment three times to obtain pretreated lavender oil; Precool 100 mL of peppermint oil at -20 °C for 12 h, then under nitrogen protection, centrifuge at -15 °C and 10,000 rpm for 30 min to obtain pretreated peppermint oil;

[0048] Step 2: Under nitrogen protection, stir 50 mL of the pretreated eucalyptus oil prepared in Step 1 and 30 mL of the pretreated lavender oil at 42 °C for 10 min, then add 25 mL of the pretreated peppermint oil and stir at 2000 rpm for 30 min. Dropwise add 10 mL of clove bud oil and 3.45 mL of Tween-80, and perform ultrasonic treatment at 80 W and 20 kHz for 5 min; Add 0.115 g of vitamin E, mix well, and let stand at 4 °C for 24 h to obtain the plant essential oil;

[0049] The specific preparation steps of the composition for air disinfection and deodorization are as follows:

[0050] Step 1: Stir and mix 100 mL of 3 wt% sodium alginate solution and glycerol evenly, then mix with 150 mL of 2 wt% chitosan solution and stir to mix evenly. Then add 0.5 g of zinc nitrate and 3.75 g of tannic acid in sequence, adjust the pH to 5, and continue stirring until homogeneous to obtain the precursor solution;

[0051] Step 2: Slowly drip 250 mL of the precursor solution prepared in Step 1 into 500 mL of 3 wt% calcium chloride and 0.05 M sodium chloride solution, maintain the temperature at 4 °C, slowly stir for 60 min, wash with deionized water, freeze-dry at -40 °C for 24 h, then immerse in 500 mL of 0.5 wt% potassium peroxymonosulfate solution, oscillate at 25 °C for 2 h, repeat washing with deionized water 3 times, and freeze-dry at -40 °C for 12 h to obtain the core;

[0052] Step 3: Disperse 2 g of nano-SiO2 in 300 mL of absolute ethanol, perform ultrasonic dispersion treatment at 60 W for 20 min, add 12 mL of cetyltrimethoxysilane, adjust the pH to 5, react under nitrogen protection in a water bath at 65 °C for 6 h, centrifuge, wash repeatedly with ethanol 3 times, and dry in vacuum at 60 °C for 12 h to obtain modified nano-SiO2; Disperse 4 g of pregelatinized starch, 1.2 g of hydroxypropyl methylcellulose, 2 g of modified nano-SiO2, and 0.288 g of polyethylene glycol in 120 mL of deionized water in sequence, adjust the pH to 6, and perform ultrasonic treatment at 60 W for 25 min to obtain a pretreated slurry; Preheat the 10 g of core prepared in Step 2 at 50 °C for 10 min, then evenly spray the pretreated slurry, with an inlet air temperature of 55 °C, an atomization pressure of 1.5 bar, a liquid spraying rate of 5 mL / min, and a time of 10 min; Treat at 70 °C and a humidity of 85% for 2 h, and dry at 50 °C for 2 h to obtain coated particles;

[0053] Step 4: Add 10 g of the coated particles prepared in Step 3 to 4.5 mL of plant essential oil preheated to 40 °C, soak under vacuum conditions for 50 min, and centrifuge at 1200 rpm for 4 min to obtain loaded particles;

[0054] Step 5: Spray a 1.5 wt% polydimethylsiloxane n-hexane solution on the 10 g of loaded particles prepared in Step 4. Under 0.3 MPa, the spraying distance is 25 cm, and the spraying amount is 8 mL / m 2 , spray 2 times at intervals of 10 min, dry with hot air at 40 °C for 1.5 h, and then cure at 80 °C for 20 min after the spraying treatment; After the spraying treatment, treat at 30 °C and 85% humidity for 60 min, then treat at 40 °C and 50% humidity for 3 h, then repeat the cyclic treatment, treat at 30 °C and 75% humidity for 30 min, then treat at 40 °C and 30% humidity for 2 h, and perform the cyclic treatment 2 times to obtain a disinfection and deodorization composition.

[0055] Example 3: A composition for air disinfection and deodorization, which comprises a core component and a shell component; The core component includes the following components: sodium alginate, chitosan, potassium peroxymonosulfate, tannic acid, zinc nitrate, glycerol, sodium chloride, and calcium chloride; The shell component includes the following components: plant essential oil, pregelatinized starch, polyethylene glycol, nano-SiO2, hydroxypropyl methylcellulose, polydimethylsiloxane, and silane coupling agent;

[0056] The plant essential oil is prepared from eucalyptus oil, lavender oil, peppermint oil, and clove bud oil, and its specific preparation steps are as follows:

[0057] Step 1: Preheat 100 mL of eucalyptus oil under nitrogen protection at 50 °C for 25 min, then perform fractional distillation. Evaporate at 85 °C, condense at -10 °C, and distill at 0.8 mbar. Discard the first 5% of the distillate; then raise the temperature to 100 °C and distill at 0.5 mbar, discarding the first 5% and the last 10% of the distillate; filter through a 0.45 μm nylon filter membrane at 60 °C to obtain pretreated eucalyptus oil; Let 100 mL of lavender oil stand at 4 °C for 48 h, filter to remove wax using a diatomaceous earth coating, use a precoat of diatomaceous earth with a wet basis thickness of 5 mm and a pore size of 10 μm, and increase the pressure from 0.1 MPa to 0.25 MPa at a rate of 0.01 MPa / min at 12 °C, and filter at a filtration rate of 1.2 L / m 2 •h. Repeat the filtration process three times to obtain pretreated lavender oil; Precool 100 mL of peppermint oil at -22 °C for 12 h, then centrifuge at -18 °C and 9000 rpm for 30 min under nitrogen protection to obtain pretreated peppermint oil;

[0058] Step 2: Under nitrogen protection, stir 48 mL of the pretreated eucalyptus oil prepared in Step 1 and 24 mL of the pretreated lavender oil at 38 °C for 15 min, then add 20 mL of the pretreated peppermint oil, stir at 2000 rpm for 25 min, dropwise add 8 mL of clove bud oil and 2.5 mL of Tween-80, and perform ultrasonic treatment at 70 W and 20 kHz for 6 min; Add 0.1 g of vitamin E, mix well, and let stand at 4 °C for 24 h to obtain the essential oil;

[0059] The specific preparation steps of the composition for air disinfection and deodorization are as follows:

[0060] Step 1: Stir and mix 100 mL of 2.5 wt% sodium alginate solution and glycerol evenly, then mix with 120 mL of 1.5 wt% chitosan solution, stir and mix evenly, then add 0.396 g of zinc nitrate and 3.3 g of tannic acid in sequence, adjust the pH to 5, and continue stirring until homogeneous to obtain the precursor solution;

[0061] Step 2: Slowly drop 220 mL of the precursor solution prepared in Step 1 into 440 mL of 3 wt% calcium chloride and 0.05 M sodium chloride solution, maintain the temperature at 4 °C, slowly stir for 50 min, wash with deionized water, freeze-dry at -40 °C for 20 h, then immerse in 440 mL of 0.5 wt% potassium peroxymonosulfate solution, oscillate at 25 °C for 2 h, repeat washing with deionized water 3 times, and freeze-dry at -40 °C for 12 h to obtain the core;

[0062] Step 3: Disperse 2 g of nano-SiO₂ in 300 mL of absolute ethanol, perform ultrasonic dispersion treatment at 60 W for 18 min, add 11 mL of dodecyltrimethoxysilane, adjust the pH to 4.5, react in a water bath at 63 °C under nitrogen protection for 6 h, centrifuge, wash repeatedly with ethanol 3 times, and dry in vacuum at 60 °C for 12 h to obtain modified nano-SiO₂; Disperse 3.5 g of pregelatinized starch, 1 g of hydroxypropyl methylcellulose, 1.8 g of nano-SiO₂ and 0.252 g of polyethylene glycol in 120 mL of deionized water in turn, adjust the pH to 6, and perform ultrasonic treatment at 60 W for 30 min to obtain a pretreated slurry; Preheat the 10 g of kernels prepared in Step 2 at 50 °C for 10 min, then evenly spray the pretreated slurry, with an air inlet temperature of 52 °C, an atomization pressure of 1.2 bar, a liquid spraying rate of 5 mL / min, and a time of 12 min; At 70 °C and a humidity of 85%, treat for 2 h, and dry at 50 °C for 1.5 h to obtain coated particles;

[0063] Step 4: Add 10 g of the coated particles prepared in Step 3 to 4 mL of plant essential oil preheated to 40 °C, soak under vacuum conditions for 60 min, and centrifuge at 1200 rpm for 5 min to obtain loaded particles;

[0064] Step 5: Spray a 1.5 wt% polydimethylsiloxane n-hexane solution on 10 g of the loaded particles prepared in Step 4. Under 0.3 MPa, the spraying distance is 22 cm, and the spraying amount is 7 mL / m 2 , spray 2 times at intervals of 10 min, dry with hot air at 40 °C for 1 h, and then cure at 75 °C for 25 min after the spraying treatment; After the spraying treatment, treat at 30 °C and 85% humidity for 50 min, then treat at 40 °C and 50% humidity for 3 h, then repeat the cyclic treatment, treat at 30 °C and 75% humidity for 30 min, and then treat at 40 °C and 30% humidity for 2 h, and perform the cyclic treatment 2 times to obtain a disinfection and deodorization composition.

[0065] Comparative Example 1: The operation of Comparative Example 1 is basically the same as that of Example 2. The difference between it and Example 2 is only that after the spraying in Step 5 of Comparative Example 1, it is directly dried at 40 °C to obtain a disinfection and deodorization composition.

[0066] Comparative Example 2: The operation of Comparative Example 2 is basically the same as that of Example 2. The difference between it and Example 2 is only that all the plant essential oils in Comparative Example 2 are not pretreated.

[0067] Comparative Example 3: The operation of Comparative Example 3 is basically the same as that of Example 2. The difference between it and Example 2 is only that only the pretreated eucalyptus oil is used in Comparative Example 3.

[0068] Comparative Example 4: The operation of Comparative Example 4 was basically the same as that of Example 2, and the difference between it and Example 2 was only that in Comparative Example 4, the core components such as sodium alginate, chitosan, and zinc nitrate were directly blended with the outer shell components such as plant essential oil and pregelatinized starch, and then obtained by spray drying.

[0069] Performance test:

[0070] Sterilization and deodorization test: Escherichia coli, Staphylococcus aureus, and Aspergillus niger suspensions (10 6 CFU / mL) were atomized and injected into the test chamber (1 m 3 , temperature 25 ± 2 °C). The usage amount of the composition samples prepared in Example 2 and Comparative Examples 1 to 4 was 10 g / m 3 . After equilibration for 30 min, the humidity was adjusted to 80%. Microorganisms in the air were collected at 0 h, 2 h, 6 h, 12 h, and 24 h. Control group: no composition, under the same humidity condition; Escherichia coli and Staphylococcus aureus were cultured at 37 °C for 48 h for counting, and Aspergillus niger was cultured at 25 °C for 72 h for counting. Sterilization rate (%) = (number of colonies in the control group - number of colonies in the test group) / (number of colonies in the control group) × 100%. The results are as Figure 1 、 Figure 2 and Figure 3 shown;

[0071] The same test was carried out on the odor source (H2S 20 ppm, NH3 50 ppm). The gas was collected every 30 min, and the total detection duration was 6 h. The change in the detected concentration was calculated. Deodorization rate (%) = (C 初始浓度 - C 某时刻浓度 ) / C 初始浓度 × 100%. The removal rates at 0, 1, 3, and 6 h were statistically analyzed. The results are as Figure 4 、 Figure 5 shown.

[0072] From Figure 1 、 Figure 2 and Figure 3 the results, it can be seen that the composition prepared by the present invention has excellent sterilization performance; from the results of Comparative Example 1 and Example 2, it can be seen that the shell PDMS did not form dynamic pores, and the concentration of essential oil decreased rapidly after burst release, and the nuclear layer gel did not swell and dissolve sufficiently with water, which may have led to Zn 2+The release rate is insufficient, which in turn significantly affects the sterilization rate. From the results of Comparative Example 2 and Example 2, it can be seen that the resin residue in eucalyptus oil may block the pores of the shell layer, reducing the diffusion efficiency of the essential oil. In addition, the deposition of lavender oil wax may cause hindrance to the swelling of HPMC, resulting in the failure of humidity response, and thus affecting the sterilization effect. From the results of Comparative Example 3 and Example 2, it can be seen that the penetration of eugenol into the fungal cell wall is missing, and there is no menthol to instantaneously neutralize sulfur-containing metabolites, and the microbial repair mechanism is not blocked, resulting in a significant decrease in the sterilization effect. From the results of Comparative Example 4 and Example 2, Zn 2+ coming into direct contact with the essential oil may cause complex precipitation, resulting in the inactivation of active ingredients. Moreover, without core-shell isolation, the components of the inner core and the outer shell compete for release, and the concentration drops sharply after 6 h, resulting in a significant decrease in the antibacterial effect.

[0073] From Figure 4 and Figure 5 the results, it can be seen that the composition prepared by the present invention has excellent deodorizing effects and excellent reaction scavenging effects on H2S and NH3. From the results of Comparative Example 3 and Example 2, it can be seen that eucalyptol has a relatively high scavenging effect on H2S, but the lack of the synergistic effect of lavender oil significantly affects the scavenging effect on NH3.

[0074] Mechanical strength test: Take 1 g of the composition samples prepared in Example 2 and Comparative Examples 1 and 4 (dried to constant weight at 40 °C), and evaluate the mechanical strength by treating them at a frequency of 20 Hz and an amplitude of 5 mm for 24 h. The particle breakage rate (sieved through a 40-mesh sieve) = broken mass / total mass × 100%. The results are as Figure 6 shown.

[0075] From Figure 6 the results, it can be seen that the disinfection and deodorization composition prepared by the present invention has excellent mechanical strength, which can effectively ensure the stability during storage, transportation and use. From the results of Comparative Example 1 and Example 2, it can be seen that the PDMS coating has not undergone humidity cycling treatment, the hydrophobic membrane is loosely combined with the shell layer, and the hydrogen bond interlock between the core layer gel and the shell layer starch is not fully formed. The shell layer is prone to local peeling due to the concentration of vibration stress, and the swelling of the core layer after water absorption is aggravated after exposure, resulting in rupture. From the results of Comparative Example 4 and Example 2, it can be seen that sodium alginate and pregelatinized starch are directly blended without core-shell isolation, and the material compatibility is extremely poor. In addition, zinc nitrate comes into direct contact with the essential oil, which may trigger a metal ion-terpene complexation reaction, thus significantly affecting the structural stability.

[0076] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made in these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A composition for air disinfection and deodorization, characterized in that, It consists of a core component and a shell component; the core component includes the following components: sodium alginate, chitosan, potassium peroxymonosulfate, tannic acid, zinc nitrate, glycerol, sodium chloride and calcium chloride; the shell component includes the following components: plant essential oil, pregelatinized starch, polyethylene glycol, nano-SiO2, hydroxypropyl methylcellulose, polydimethylsiloxane and silane coupling agent; The plant essential oil is prepared from eucalyptus oil, lavender oil, peppermint oil and clove bud oil, and the specific preparation steps are as follows: Step 1: Under nitrogen protection, preheat the eucalyptus oil, and then perform fractional distillation treatment, retaining 1,8-cineole; filter with a nylon membrane to obtain pretreated eucalyptus oil; let the lavender oil stand at 4°C, and then filter and dewax with a diatomaceous earth coating to obtain pretreated lavender oil; Pre-cool the peppermint oil, and then perform centrifugation treatment at a low temperature below zero under nitrogen protection to obtain pretreated peppermint oil; Step 2: Under nitrogen protection, stir the pretreated eucalyptus oil and pretreated lavender oil prepared in Step 1 at 35-42°C for 10-20 min, then add the pretreated peppermint oil, stir at 2000 rpm for 20-30 min, dropwise add clove bud oil and Tween-80, perform ultrasonic treatment, add vitamin E, mix evenly and then let stand to obtain the plant essential oil.

2. The composition for air disinfection and deodorization according to claim 1, wherein In Step 1, the fractional distillation step is evaporation at 85°C, condensation at -10°C, distillation treatment under 0.8 mbar, and discarding the first 5% of the distillate; then raise the temperature to 95-105°C, perform distillation treatment under 0.5 mbar, and discard the first 5% and the last 10% of the distillate.

3. The composition for air disinfection and deodorization according to claim 2, wherein, In Step 1, the use of diatomaceous earth coating for wax removal by filtration is to use a precoat of diatomaceous earth with a wet-based thickness of 5 mm and a pore size of 10 μm. At 10 - 15 °C, the pressure is increased from 0.1 MPa to 0.25 MPa at a rate of 0.01 MPa / min, and filtration is carried out at a filtration rate of 1 - 1.5 L / m 2 •h, and the filtration treatment is repeated three times.

4. The composition for air disinfection and deodorization according to claim 3, characterized in that, The silane coupling agent is any one of octyltriethoxysilane, dodecyltrimethoxysilane and hexadecyltrimethoxysilane.

5. A method for preparing a composition for air disinfection and deodorization according to any one of claims 1-4, characterized in that, The specific preparation steps are as follows: Step 1: Stir and mix the sodium alginate solution and glycerol evenly, then add the chitosan solution, stir and mix evenly, then add zinc nitrate and tannic acid in sequence, adjust the pH, and continue to stir until homogeneous to obtain a precursor solution; Step 2: Slowly drop the precursor solution prepared in Step 1 into the calcium chloride and sodium chloride solution, maintain the temperature at 4°C, slowly stir, wash with deionized water, freeze-dry at -40°C for 12-24 h, then immerse in the potassium peroxymonosulfate solution, oscillate, repeat washing with deionized water, and freeze-dry at -40°C for 12 h to obtain the core; Step 3: Disperse nano-SiO2 in absolute ethanol, perform ultrasonic dispersion treatment, add a silane coupling agent, adjust the pH, react under water bath nitrogen protection, centrifuge, repeat washing with ethanol, and vacuum dry to obtain modified nano-SiO2; disperse pregelatinized starch, hydroxypropyl methylcellulose, modified nano-SiO2 and polyethylene glycol in deionized water in sequence, adjust the pH, and perform ultrasonic treatment and mixing to obtain a pretreated slurry; Preheat the core prepared in Step 2, then evenly spray the pretreated slurry, perform humid heat treatment and drying treatment to obtain coated particles; Step 4: Add the coated particles prepared in Step 3 to the preheated plant essential oil, soak and centrifuge under vacuum conditions to obtain loaded particles; Step 5: Spray the polydimethylsiloxane n-hexane solution onto the loaded particles prepared in Step 4. After the spraying treatment, treat at 30°C and 85% humidity for 30 - 60 min, then treat at 40°C and 50% humidity for 3 h, and then repeat the cyclic treatment to obtain the disinfection and deodorization composition.

6. A preparation method of the composition for air disinfection and deodorization according to claim 5, characterized in that, In Step 1, the volume ratio of the sodium alginate solution, glycerol, and chitosan solution is 1:0.08 - 0.12:1 - 1.5; in Step 3, the dosage ratio of the nano-SiO2, absolute ethanol, and silane coupling agent is 1 g:150 mL:5 - 6 mL; the dosage ratio of the pregelatinized starch, hydroxypropyl methylcellulose, modified nano-SiO2, and deionized water is 3 - 4 g:0.8 - 1.2 g:1.5 - 2 g:120 mL.

7. A method for preparing the composition for air disinfection and deodorization according to claim 6, characterized in that, In Step 3, the operation of spraying the pretreatment slurry is to have an inlet air temperature of 50 - 55°C, an atomization pressure of 1 - 1.5 bar, a liquid spraying rate of 5 mL / min, and a time of 10 - 15 min.

8. A method for preparing the composition for air disinfection and deodorization according to claim 7, characterized in that, In Step 4, the dosage ratio of the cladding particles to the plant essential oil is 1 g: 0.35 - 0.45 mL; in Step 5, the spraying operation is carried out at 0.3 MPa, with a spraying distance of 20 - 25 cm and a spraying amount of 5 - 8 mL / m 2 , spray twice at intervals of 10 min, dry with hot air at 40 °C for 1 - 2 h, and then cure at 70 - 80 °C for 20 - 30 min.

9. A method for preparing the composition for air disinfection and deodorization according to claim 8, characterized in that, In Step 5, the operation of the repeated cyclic treatment is to treat at 30°C and 75% humidity for 30 min, then treat at 40°C and 30% humidity for 2 h, and perform the cyclic treatment 2 times.

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